Diastylis enodis, Gerken, Sarah, 2015

Gerken, Sarah, 2015, New Zealand Diastylidae and Gynodiastylidae (Crustacea: Cumacea), Zootaxa 4031 (1), pp. 1-77 : 28

publication ID	https://doi.org/ 10.11646/zootaxa.4031.1.1
publication LSID	lsid:zoobank.org:pub:19E72EB1-B55C-40C0-AD11-23BA6E97D438
DOI	https://doi.org/10.5281/zenodo.6122521
persistent identifier	https://treatment.plazi.org/id/C70EEC59-6E3E-FFD9-FF24-1DE6FC657B46
treatment provided by	Plazi
scientific name	Diastylis enodis
status	sp. nov.

Treatment

Diastylis enodis View in CoL n. sp.

( Figs. 14–15 View FIGURE 14 View FIGURE 15 )

Material examined. Holotype: preparatory female, NIWA 0 93200, TAN0705/24, 44.1208°S, 174.8432°E – 44.1242°S, 174.8448°E, 512–513 m, 4 April 2007. Paratype: preparatory female (dissected), NIWA 0 93180, TAN0705/36, 43.8298°S, 176.7102°E – 43.8298°S, 176.7102°E, 479 m, 5 April 2007.

Diagnosis. Female and subadult male. Carapace elongate, smooth, with few short setae anteriorly; ventral margin smooth; antennal notch oblique. Eyelobe without lenses. Pseudorostrum acute, 0.16 times carapace length anterior of eyelobe. Antennule article 2 subequal to article 3. Maxilliped 3 ischium not produced. Pereopod 1 basis ischium merus together longer than carpus propodus dactylus together, carpus and propodus subequal, propodus shorter than dactylus. Pereopod 2 carpus 5 times propodus length. Pereopods 3–4 without exopods. Telson with 10–11 lateral setae, more than 0.5 times length of uropod peduncles.

Adult male. Unknown.

Etymology. The species is named from the Latin enodis , meaning smooth, without knots, in reference to the smooth carapace without any ornamentation except tiny reticulations.

Description. Preparatory female holotype 7.4 mm, preparatory female paratype 8.2 mm. Body ( Figs. 14 View FIGURE 14 A–B). Carapace eyelobe present, as wide as long, but without lenses or obvious visual elements. Pleon unornamented.

Antennule ( Fig. 14 View FIGURE 14 C) peduncle article 1 as long as articles 2 and 3 together, with simple and plumose setae; article 2 with few small setae; article 3 with few simple setae. Main flagellum of 3 articles, with 2 aesthetascs and simple seta; accessory flagellum of 2 articles, more than half length of main flagellum article 1, with simple setae.

Antenna ( Fig. 14 View FIGURE 14 C) of 3 articles, with plumose setae.

Mandibles ( Fig. 14 View FIGURE 14 D) navicular, with row of 15 microserrate setae medially.

Maxillule ( Fig. 14 View FIGURE 14 E) with 2 endites, palp with 2 microserrate setae.

Maxilla ( Fig. 14 View FIGURE 14 F) with 3 endites; broad endite medial row of setae pedunculate; narrow endites with microserrate setae.

Maxilliped 1 ( Fig. 14 View FIGURE 14 G) carpus without beak setae, with simple setae; lateral margin of propodus strongly serrate.

Maxilliped 2 ( Fig. 14 View FIGURE 14 H) basis with many short simple setae on medial margin; ischium not visible.

Maxilliped 3 ( Fig. 14 View FIGURE 14 I) 100:8:9:13:15:8; basis produced distolaterally with 5 plumose setae, with pappose setae.

Pereopod 1 ( Fig. 15 View FIGURE 15 A) 100:7:15:37:35:23; basis with many plumose setae; dactylus with simple setae terminally.

Pereopod 2 ( Fig. 15 View FIGURE 15 B) 100:8:21:55:11:24; basis with alternating plumose and short simple setae, 2 simple setae distally; merus to dactylus with short and long simple setae; dactylus with long simple setae terminally; exopod longer than basis, with many short setae on basal article.

Pereopod 3 ( Fig. 15 View FIGURE 15 C) 100:8:24:16:11:8; basis, ischium and merus with plumose setae; carpus and propodus with simple and annulate setae; dactylus terminal seta simple; exopod absent.

Pereopod 4 ( Fig. 15 View FIGURE 15 D) 100:13:32:26:10:10; basis with plumose setae; ischium and merus with simple setae; carpus and propodus with simple and annulate setae; dactylus terminal seta simple; exopod absent.

Pereopod 5 ( Fig. 15 View FIGURE 15 E) 100:24:43:43:19:19; basis with plumose setae; merus with simple setae; carpus and propodus with simple and annulate setae; dactylus terminal seta simple.

Telson ( Fig. 15 View FIGURE 15 F) 1.9 times as long as pleonite 6, with 10–11 short setae with single setule laterally, terminal setae simple.

Uropods ( Fig. 15 View FIGURE 15 F) peduncles with many short setae with single setule medially; endopod triarticulate, with many short setae with single setule medially, terminal seta short, simple with single setule; exopod longer than endopod, with many short simple setae, terminal seta long.

Distribution. Chatham Rise, New Zealand, 479– 513 m.

Remarks. Diastylis enodis is most similar to D. dasys ; however, the carapace is more elongate, and there are no spines and no long setae on the carapace, the carapace is very smooth.